object Collection {
  def main(args: Array[String]): Unit = {

    //定义一个集合
//    var v1 = collection.immutable.Stack(1,2,3)
//    v1(0) = 100
//    println(v1(0))
    val v2 = collection.mutable.Stack(1,2,3)
    println(v2)
    v2(0) = 100
    println(v2)

  }
}
